trivial: Update licenses

All of these files saw significant changes, so we update the license to
reflect this.

libplatsupport,imx: Remove all timer constants

Now that the addresses of the registers and the IRQ numbers are being
read from the DTB, we no longer need these constants.

libplatsupport,imx: Move HW ops to driver level

Timer resource initialisation and the management of interrupts should
belong in the driver level and not the timer abstraction level. This
commits moves those operations down into the driver level for the i.MX
platforms.

imx8m-mcs adjust frequency

Adjust gpt frequency to synchronize with
kernel timer.

Added initial i.MX8M Mini EVK Platform support

This adds enough to use gpts and serial for sel4test